Heat Evolution and Electrical Work of Batteries as a Function of Discharge Rate: Spontaneous and Reversible Processes and Maximum Work
Robert J. Noll and Jason M. Hughes; J. Chem. Educ., 2018, 95, pp 852−857.
This article describes an experiment in which students compare the enthalpy change of the useful electrical work to the heat lost from the electrochemical reaction in batteries. AA alkaline batteries are installed in a battery holder and connected to a heater resistor and sensors. The apparatus is suspended in a Dewar flask and the water is stirred gently at 200 rpm. The potential, current, and temperature are measured over a period of 30 minutes. The students use a Current Probe and a Voltage Probe connected to a computer running through a LabQuest Mini to measure the work output of the battery. The waste heat produced is measured calorimetrically using a Stainless Steel Temperature Probe. This activity combines concepts from electricity, electrochemistry, and thermodynamics in one experiment.
Measuring the Force between Magnets as an Analogy for Coulomb’s Law
Samuel P. Hendrix and Stephen G. Prilliman; J. Chem. Educ., 2018, 95, pp 833−836.
The authors describe a simple demonstration to illustrate the relationship between charged particles as described by Coulomb’s law. They use a Dual-Range Force Sensor mounted on a LEGO® platform. The sensor is connected to a computer with a Go!Link and monitored with our free Logger Lite software. A neodymium magnet is attached to the end of a screw. It is installed where the hook or bumper would normally go in the sensor. A second neodymium magnet is mounted to another LEGO® piece that is mounted on the same LEGO® platform. Attractive and repulsive forces can be demonstrated by switching the orientation of one of the magnets. The force between the magnets is plotted as a function of distance using the Events with Entry mode of data collection. This plot represents a Coulomb’s law force between charged particles and would be useful when teaching ionization, bonding, intermolecular forces, lattice energy, and PES (photoelectron spectroscopy).
Using Open-Source, 3D Printable Optical Hardware To Enhance Student Learning in the Instrumental Analysis Laboratory
Eric J. Davis, Michael Jones, D. Alex Thiel, and Steve Paul; J. Chem. Educ., 2018, 95, pp 672−677.
The authors describe the ability to use 3D printing technology to construct analytical instruments. They also discuss how to make the components of an absorbance spectrometer. Various mounts, posts, and slits are printed on a 3D printer are mounted on a platform with lenses and diffraction gratings with light sources and detectors. Even cuvette holders are fabricated. Common full-absorption spectra and Beer’s law plots are done with copper (II) sulfate solution. The results are compared to those from a Go Direct® SpectroVis® Plus Spectrophotometer. The plots of absorbance vs. wavelength and absorbance vs. concentration from the 3D-printed spectrometer compare favorably with those produced by the SpectroVis Plus.
Penny Snetsinger and Eid Alkhatib; J. Chem. Educ., 2018, 95, pp 636−640.
The goal of this activity is to provide students with the opportunity to design an experiment that studies the effect of activated carbon on dyes. Students select dyes to study as well as conditions to vary such as pH, salinity, water hardness, and time of contact between the dye and the carbon. The experiment lasts multiple weeks to provide ample time for the students to vary experiment conditions and to analyze their results. Additionally, students use various analytical statistics and techniques to evaluate the outcome of their experiments. They also employ a factorial experiment design that allows them to simultaneously vary more than one variable. They used a Beer-Lambert plot to spectrophotometrically determine the concentration of dye left in the solution after exposure to the activated carbon. Students use a Go Direct® SpectroVis® Plus Spectrophotometer in this experiment.
Physicians as the First Analytical Chemists: Gall Nut Extract Determination of Iron Ion (Fe2+) Concentration
Mary T. van Opstal, Philip Nahlik, Patrick L. Daubenmire, and Alanah Fitch; J. Chem. Educ., 2018, 95, pp 456−462.
This article describes a guided inquiry activity that measures the iron in drinking water, using oak gall nut extract. This activity is geared toward students who are interested in medical careers. The idea is to use a naturally occurring substance to react with the iron ion in a solution and to form a colored solution from which the iron concentration can be determined. The students create standard Beer-Lambert plots of absorbance vs. concentration, then measure the absorbance of the gall-iron solution to determine the concentration of the iron ion. In this experiment students use a Go Direct® SpectroVis® Plus Spectrophotometer.
Measuring Yeast Fermentation Kinetics with a Homemade Water Displacement Volumetric Gasometer
Richard B. Weinberg; J. Chem. Educ., 2018, 95, pp 828−832.
This article describes how to build a volumetric gasometer from simple equipment such as plastic bottles and tubing. The students then use the device to measure the volume of carbon dioxide produced while sugar is metabolized by yeast. As the CO2 is produced the water in one bottle is displaced into a second bottle. The rate of metabolism is measured by timing the amount of water displaced. The activity is appropriate for students from middle school well into college and describes how to use the experiment with different age groups. Some of the inspiration for this activity came from Experiment 12A, “Respiration of Sugars by Yeast” from our Biology with Vernier lab book and “Sugar Metabolism with Yeast” from our lab book Investigating Biology through Inquiry.
In July, more than 100 students from 35 countries used our Go Direct sensors to test the water in Ireland’s Killarney National Park as part of the 2018 GLOBE Learning Expedition (GLE). This event is part of the GLOBE Program and is held every few years in different locations around the world. The GLE brings together students, teachers, and scientists for a week of sharing and learning about science, the environment, and each other’s cultures. As part of this year’s student field experience, Go Direct sensors were used to measure temperature, pH, conductivity, and dissolved oxygen levels along the Deenagh River. This beautiful river runs along the edge of the park, near the town of Killarney. The students’ sensor data, along with a survey of macroinvertebrates, indicated that the Deenagh is in excellent health.
Using Go Direct sensors wirelessly in this type of environment was a game-changer for many students and their teachers. The new Go Direct® Optical Dissolved Oxygen Probe was especially useful as it reports not only dissolved oxygen concentration, but temperature and atmospheric pressure as well. By connecting Go Direct sensors via Bluetooth® wireless technology, one student can stay safely on the shore with a LabQuest 2, mobile phone, or other device, while another student holds the sensor in the water. Everyone agreed that the simplicity and accuracy of Go Direct sensors make them an excellent choice for students conducting field work.
We are proud to work with the GLOBE Program, an international science and education program whose mission is to promote the teaching and learning of science, enhance environmental literacy and stewardship, and promote scientific discovery. For more information, visit the GLOBE Program page»
This guide has many useful resources for incorporating climate change lessons into science programs and has been mailed to science teachers at every school in seven states. It is also available as a free download.
You can now use our wireless Go Direct sensors with the Digital Control Unit (DCU) to control small electronic devices (e.g., motors, LEDs, and lights). Last year, you may recall, we added the capability to control the DCU from LabQuest 2. This year, when LabQuest 2 gained the ability to connect with Go Direct sensors, we once again expanded the DCU’s capability. Wirelessly connect your Go Direct sensor(s) to LabQuest 2, connect the DCU to LabQuest 2, and program the DCU to turn on components based on the sensor values.
With Go Direct sensors and the DCU, you can use output from a heart rate monitor to light up LEDs that help test subjects maintain a target heart rate. Or, if your students struggle to stay awake, you can have them create an alarm that triggers when carbon dioxide levels get too high in your classroom. You could even program a fan to turn on and bring in some fresh air!
We have also created a kit of components that run on DC power in order to make it easier for you to integrate the DCU into your classroom. The Digital Control Unit Power Output Kit contains lights, LEDs, and a motor, along with connecting wires. We believe this will make it much easier to integrate simple programming logic, the engineering design process, and process control concepts into your science or engineering classroom.
For those of you who may be new to the Digital Control Unit, the device is designed to turn on a DC powered electrical component based on simple logic statements (greater than or equal to, or less than or equal to) associated with sensor values or time. It can be set up and controlled in Logger Pro 3 software or the LabQuest app. Compound statements using “and”, “or”, “until” statements allow for fairly complex control. For more information go to Digital Control Unit page.
Instrumentation is used in the undergraduate chemistry curriculum to help demonstrate the fundamental aspects of chemical reactions and demonstrate how it can be used to determine certain properties of a chemical system. For example, absorbance spectroscopy teaches students about transmission and absorption of radiation by a compound and how these measurements can be used to determine concentration or chemical reaction order. Chromatography illustrates to students how the structure of compounds can help isolate them from others. When certain techniques are coupled together, the concepts are layered and even more can be learned about the system being studied.
Flash photolysis spectroscopy is a type of time-resolved absorbance spectroscopy that helps students investigate chemical reaction order as well as the basics of photochemistry. Flash photolysis is often referred to as a “pump-probe technique” because it involves an excitation source or a “pump” and a detection source or a “probe”. This technique was so groundbreaking that the 1969 Nobel Prize in Chemistry was awarded to the scientists who developed it.
The diagram below shows a typical flash photolysis setup. In this system, white light from an LED light source probes any spectral changes made in the system by the excitation light pulse. A xenon flash lamp provides the photo-excitation pulse. The white light from the LED source is focused on the sample. From the sample this beam goes through a wavelength filter as it is focused on a photodiode, which detects this light’s intensity. When the xenon lamp is flashed, an intense near-UV, white light pulse enters the sample. If it causes changes in the absorption of the sample at the filter’s wavelength, the detector measures these changes. The voltage from the detector is collected, digitized, and stored as a function of time.
With recent advances in photochemistry in a number of disciplines, understanding photo-induced chemical kinetics is quickly becoming an essential part of the undergraduate chemistry curriculum. Due to limitations in affordable instrumentation, photochemical kinetics is often left to the textbook alone. The Vernier Flash Photolysis Spectrometer is an affordable option available to instructors to help students get hands-on experience with this important technique. We provide a number of free experiments to get you started, including one that involves exploration of a simple light-induced, cis-trans isomerization of Congo Red. Congo Red is a diazo dye that is a derivative of azobenzene. When light excites the ground state trans- form at its visible broadband absorbance, some ground state molecules are converted to a higher energy cis- form instantaneously (on this time scale, at least). The cis- state is metastable with respect to the trans- ground state resulting in slow conversion back to this trans- ground state, as shown in the state diagram below. The loss of the absorbance at 600 nm observed by the Vernier Flash Photolysis Spectrometer gives students the opportunity to follow the progress of a thermal cis-trans isomerization and measure its rate on timescales that cannot be achieved by traditional mixing methods.
The data and analysis provides an opportunity for discussion with students about various topics, including perturbation kinetics, photochemistry, fast kinetics, and bimolecular rate constants. This experiment, and others like it, allow for easy incorporation of time-resolved spectroscopy into the undergraduate physical chemistry, biochemistry, organic chemistry, and inorganic chemistry curriculums.
At Vernier, we focus on sourcing from local venders, generating our own solar power, and providing our employees with annual TriMet passes to encourage the use of public transpiration. Our building is also LEED Gold certified. Vernier employees participate in multiple commuter challenges, such as the Bike More Challenge, that encourages participants to ride their bikes to work. Our two on-site, certified Master Recyclers work with many local recycling organizations to prevent recyclable materials from ending up in landfills, and our Green Team of Vernier employees continues to make improvements to our processes and encourage sustainability throughout the company. We are also founding members of the Oregon Business Alliance for Climate and have signed the We Are Still In pledge.
The awards were announced in the June 2018 edition of Oregon Business Magazine. For more information about the sustainable practices that we implement every day, visit our environment page.
By Janey Camp, Vanderbilt Engineering Faculty Member and Education Outreach Chair for the Nashville Branch ASCE
On March 3, 2018, the Nashville Branch of the American Society of Civil Engineers (ASCE) hosted its 10th Music City Bridge Competition with 54 bridges submitted for qualifications testing and 38 bridges tested to failure. The competition is open to any and all high school students in Middle Tennessee and serves as a qualifying competition for the Illinois Institute of Technology’s International Bridge Building Contest. Winners of the Music City Bridge Competition are based upon a calculated efficiency of how much mass the bridge holds divided by the mass of the bridge.
For the past two years students have used the Vernier Structures & Materials Tester (VSMT) to test their bridges. The VSMT allows students to test bridges faster and easily display the results of bridge performance
Students arrived at the competition with their bass wood bridges completely constructed, and the bridges were checked to see if they qualified to be tested. In the past, testing was conducted by a team of volunteers who helped position a large pan under the loading platform that was then attached to the bridge. Students would add small concrete weights to the pan until the bridge shattered.
Now, with the VSMT, students can see when the bridge fails without necessarily destroying the bridge by gradually loading the bridge using the loading wheel at the bottom of the tester. The LabQuest 2 interface and Logger Pro software allowed for calculating the efficiency quickly and accurately, as opposed to manually counting and totaling the concrete weights. The students seem to really enjoy being able to watch the results in real time on the screens projecting the Logger Pro output; comparing when and at what load each others’ bridge broke.
Thanks to Vernier for their support of the Nashville Branch’s bridge competition!
This year’s winners were:
1st place to Nancy Hoang, Overton High School, Nashville, TN
2nd place to Bryan Galvan, Overton High School, Nashville, TN
3rd place to Kalei Hair and Maria Aguire, Portland High School, Portland, TN
This is the second year the National Science Education Leadership Association (NSELA) and Vernier Software & Technology have co-sponsored the Vernier Emerging Science Education Leader Scholarship (VESELS). This partnership grants a $500 scholarship to six emerging science leaders to attend the annual NSELA Summer Leadership Institute (SLI). This year, the SLI was held in Philadelphia in July.
The scholarship program was specifically designed to recognize emerging leaders at the school, district, state or informal level who have been in their role for three years or less. Applicants submitted a resume or vita, a support letter from a supervisor, and a personal letter illustrating evidence of their own emerging leadership.
In addition to the scholarship, awardees get the opportunity to work with an NSELA mentor to help them apply what they learned during the institute to their classroom.
This year’s winners are:
Alyssa Mocharnuk, Science Department Head at Foxborough Public Schools in Foxborough, MA
Amy Hochschild, 6th Grade Science Teacher at Berkshire Local Schools in Burton, OH
Brianna Greco, Science & ESL Teacher at Omaha Public Schools in Omaha, NE
Jennifer Gibson, 5th Grade Science Teacher at Midway Independent School District in Waco, TX
Katrina Reno, Instruction Coach at Moss Point School District in Moss Point, MS
Dylann Pinkman, Middle School Science Liaison and Teacher at Lincoln Public Schools in Lincoln, NE
When it comes to bringing data collection to the classroom, knowing where to start can be tricky. The team at Vernier Software & Technology compiled a list of our favorite experiments from our lab books—from elementary school science to college-level experiments—to point you in the right direction.
In this experiment, students study the effect of increasing the concentration of an ionic compound on conductivity. During the experiment, students use a Conductivity Probe or Go Direct® Conductivity Probe to measure the conductivity of solutions, investigate the relationship between the conductivity and concentration of a solution, and investigate the conductivity of solutions resulting from compounds that dissociate to produce different numbers of ions. A video demonstrating how to conduct this experiment is available here.
In this experiment, students titrate a hydrochloric acid solution with a sodium hydroxide solution using a Go Direct® Drop Counter in the process. They then use a pH sensor to monitor changes in pH as the sodium hydroxide solution is added to a hydrochloric acid solution and plot a graph of pH vs. volume. Students then use the graph to determine the equivalence point of the titration and use these results to calculate the concentration of the hydrochloric acid solution. A short video demonstrating how to conduct an acid base titration using Vernier technology is available here.
Using either a Low-g Accelerometer or Go Direct® Acceleration Sensor, students measure the centripetal acceleration on a record turntable. They also determine the relationship between centripetal acceleration, radius, and angular velocity, as well as determine the direction of centripetal acceleration.
Using a EKG Sensor or Go Direct® EKG Sensor, this experiment enables students to graph their heart’s electrical activity, determine the time interval between EKG events, and calculate heart rate based on their EKG recording.
Students build their own functioning wind turbine with Vernier Energy Sensor and a KidWind by Vernier experiment kit. During the experiment, students explore how wind turbines turn, predict variables that affect how fast a wind turbine turns, and investigate the effect of fan speed on the power output of a wind turbine. This video provides an overview of the activity using a Go Direct® Energy Sensor.
While these are some of our favorite experiments from our lab books, we love hearing about new, innovative lessons and projects using Vernier technology. If you are planning something cool for this school year, let us know at firstname.lastname@example.org
Graphical Analysis™ 4 app keeps getting better. New in the last several releases is support for photogates, which means you can now use your Vernier photogates with a Chromebook™. The much-requested photogate feature is part of a project to give physics instructors more tools in our free Graphical Analysis app, including support for the Motion Encoder Cart, Rotary Motion Sensors (Go Direct® Rotary Motion Sensor and Rotary Motion Sensor versions), the Projectile Launcher, and the novel new Go Direct® Sound, which combines waveform and sound intensity measurements.
In addition, with new tablet versions now available, Graphical Analysis has the same core feature set and appearance on Windows®, macOS®, ChromeOS™, Android™, and iOS. You can have a mixed set of devices in a classroom, and everyone can do a full spectrum of experiments, regardless of device. Procedures learned on one platform work everywhere. Files saved on one device can be opened on another, even if it is a different platform. Because device screen sizes vary widely, there is now an option to increase the size of text and other labels so that graphs are more readable on large screens.
Support for Graphical Analysis for physics is included in the 4th edition of Physics with Vernier, which has versions of activities written for students using Graphical Analysis on any platform. Experiments written for Graphical Analysis are also included with the 4th editions of Chemistry with Vernier and Biology with Vernier.
Our largest software development team is working on Graphical Analysis 4. New versions are released every few months, so keep looking for new features and tools. We have great plans for the rest of the school year to keep instructors and students in all disciplines engaged in doing science. This most recent push emphasized features of particular use to physics students. Prior releases have focused on chemistry and biology. If you have not tried Graphical Analysis recently, we think you’ll find that it has grown to be a useful tool for the most common experiments in these fields and more.
Graphical Analysis 4 works with our Go Direct sensors on all platforms and with most of our wired LabQuest sensors. As a result, making the jump from computer to Chromebook has become much easier. Best of all, Graphical Analysis 4 is free.